Circumgalactic Medium at High Halo Masses-Signatures of Cold Gas Depletion in Luminous Red Galaxies

We study ultraviolet H I and metal-line transitions in the circumgalactic medium (CGM) of 15 massive, quenched luminous red galaxies (LRGs) at redshift z similar to 0.5 and with impact parameters up to 400 kpc. We selected eight LRG-CGM systems to study general properties of the CGM around LRGs, while the other seven are already known to contain cool CGM gas from Mg II optical studies (Mg II-LRGs). In the general LRG population, we detect H I in four of eight LRGs, in all cases with N-H I < 10(16.7)cm(-2). In contrast, all Mg II-LRGs show H I; for four LRGs, the H I column density is N-H I greater than or similar to 10(18) cm(-2). The CGM of LRGs also shows low and intermediate ionized lines (such as C III, C II, Si III, and Si II) and highly ionized lines of O VI (we detect O VI around five of seven Mg II-LRGs and one of eight in the random sample). Next, we combine our sample with literature LRGs and less than or similar to L* galaxies, and we find that while for less than or similar to L* galaxies CGM H I Ly alpha absorption is stronger as galaxies are more massive, the cool CGM traced by H I Ly alpha is suppressed above stellar masses of M* similar to 10(11.5) M-circle dot. While most LRG-CGM systems show weak or nondetectable O VI (equivalent width < 0.2 angstrom), a few LRG-CGM systems show strong O VI 1031, which in most cases likely originates from groups containing both an LRG and a blue star-forming neighboring galaxy.